Operation Mushtarak, described as the biggest military assault in Afghanistan since the war began more than eight years ago, was initiated soon after midnight local time Saturday. The mission is backed by NATO air support.

The goal of the operation is to assist the Afghan government “in asserting its authority in central Helmand.” The operation is concentrated on Marjah, at the center of the region of the same name. A population of around 125,000 of mostly farming people has mainly fled the region, but in recent days it was impossible for the remaining residents to leave. About 1,000 Taliban are estimated to be hunkered down and prepared for a fight in the region.